Air filter



J. F. HEYN May 26, 1925.

AIR'FILTER Filed Dec. 8. 1924 2 Sheets-Sheet 2 S mi..

Patented May` 26, 1925.

UNITED STATES JEROME F. HEYN, F OMAHA,

AIR FILTER.

Application led December 8, 1924. Serial N'o. 754,821.

To all whom it may concern:

Be it known that I, JEROME F. H EYN, a citizen of the United States, residing at Omaha, in the county of Douglas and State of Nebraska, have .invented certain new and useful Improvements in Air Filters, of.

which the following is a specification.

My invention relates to filtering devices of the class suited for removing dust and particles of solid matter from air passed through the same. It is the object of my invention to provide a filter of this class especially adapted for use with the engines of motor vehicles, to prevent the introduction of dust and abrasive material with the air drawn into the engine through the carbureter. A further object is to provide a device of this character with which the filtered air supplied to the carbureter may be preheated. A further vobject is to provide an air filter in which the filter as a Whole is formed by a series of similar units, whereby the filter-area desired may be secured by the assembling of a suitable number of the units,

' and whereby a defective or damaged portion of the filter may be replaced without renewal of the entire filter. A further object is to provide, for filterunits of the character above mentioned, a casing of such construction that its capacity may be readily adapted to various numbers of the units. Further objects of' my invention relate to the particular construction of the ilter-units, and to the means for retaining them in operative combination with the casing, and will be more fully set forth hereinafter.

In the accompanying drawings Fig. 1 is a side elevation of a motor-vehicle engine equipped with an air-filter embodying my invention, Fig. 2 is a longitudinal section of the filter, some of the units being in elevation, Figs. 3, 4 and 5 are transverse sections taken, respectively, on the lines 3-, 4-4

.and 5 5 of Fig. 2, Fig. 6 is a detail axial section of one of the filter-units, and Fig. 7 is a partial 'section of one end of the casing, showing the arrangement of the packing which prevents leakage past the filter-units from the intake to the outlet compartments.

In carrying out my invention I preferably employ for the filtering mediuma strong close-woven fabric, such as is commonly used for the dust-collecting bags of vacuumcleaners. The filter-units hereinbefore mentioned are each formed 'by a section of the ,fabric having its edge portions secured to a rigid metal frame, so as to be held taut across one side of the frame. convenience of construction the metal frames are circular, and each frame comprises a pair of rings having interengaged marginal iianges between which the fabric is clamped. Referring to Fig. 6, the first frame-ring has a body-portion 10 which is substantially at at the inner portion but is slightly dished near its outer edge, and has a marginal flange 12 turned in toward the concave side titi For greatest of the dished portion. The fabric 11 1s stretched over the face of the body-portion 10 at the side thereof which has the convex margin, the fabric being carried about the flange 12 to the inner side thereof. The

second frame-ring has a short cylindrical body-portion 14,` with a narrow inturned flange 15 at one end, and an out-turned flange 16 at the other end, the latter ange fttinof Within the flange 12 of the first ring, and ie marginal portion 17 of the fabric being clamped between said flanges 12 and 16. The frame-rings and fabric may be conveniently assembled by the use of suitable dies such as are employed for the manufacture of covered buttons, and of which the i construction and use are well known. It is noted that the inward swaging of the ring-fiange 12 which effects the clamping of the fabric edges between the rings, also draws the central portions of the fabric taut, so that the same extends across the open centralportion of the ring 10 like a tympanum or diaphragm.

In the assemblage comprising the framerings and fabric, the portions which project laterally beyond the cylindrical body-portion 14 of the sec-ond ring form a rim or annular bead, and at diametrically opposite points this projecting rim or bead is indented or swaged inwardly, to form two rounded depressions or grooves 18 which at their centers extend only slightly outside the ringportion 14, being offset therefrom by merely .the thickness ofv thefabric and ofthe In the assemblage of units the grooves 18 j are alined longitudinally with each other,

and the alternate. units are reversed as to the osition of the slots 19, so that in half of t e units of the series the slots are at the lower side, and in the intervening units the'slots are at the upper side. The units are held in their assembled relation by means of a clamping-frame, comprising rings 20 and 21, and a pair of longitudinall extending rods 22 which are threaded at their extremities and provided with nuts 23 for engaging the rings 20 and 21 to press them toward each other. The clamp-rods 22 are so disposed as to extend parallel with the Series of grooves 18 in the edges of the filter-units, but are spaced laterally from said grooves, as best shown in Fig. 5. Upon the clamp-rods between the end-rin s 20 and 21 are disposed cylindrical pac ingmembers comprising series of washers 24 of felt or like compressible material, the diameters of said packing-members being such that they are pressed into the grooves 18 and against the sides of the ring-portions 14 intermediate said grooves, whereby to be in contact with the series of filterunits along continuous longitudinal lines. rIhe compressible packing material, by yielding longitudinally of the clamp-rods, permits the variations of distance between the clam -rings 2O and 21 needed to compensate tfor t e longitudinal compression of the series of filter-units when the same are clamped together, at the same timeA preserving a dust-tight joint with the lateral edges of the umts. The central opening through each of the rings 2O and 21 is of substantially the same diameter as the openings through the frame-rings 10 of the filterumts. In .the edge of each of the clamprin s 2() and 21 there is arectangular groove whlch extends peripherally of the ring between points adjacent to the openings for the clamp-rods. At the opposite edge, or between the ends of the peripherally-grooved portion, the ring is reduced or cut away to a radius substantially the same as that of the outer portions of the filter-units. In the said perlpheral groove is disposed a strip 25 of compressible packing material, such as felt, the normal transverse section of the strip being such that when it is forced into the oove it will tend to bul e therefrom at t e open outer side of t e groove. Adjacent to the clamp-rods, the sideor face of the ring adjoining the packing-washers 24 has a notch or recess 26,

shown in Figs. 5 and 7, so that said washers lmay engage the side of the packing-strip 25, as indicated clearly in the latter figure. The grooved portions of the rings 20 and 21, containing the packing-strips 25, are disposed respectively at the lower and upper sides of the assembled series of units.

"space within 'the casing into two 'compartments 28 and 29, the first including the space at the outer face of the ring 21 and about the lower side of the filter-units, and the other com artment includingv the space .above the Iter-units and at the outer 'face of the ring 20. The casin cylinder 27 is provided with heads 30 eac havin an inwardly extendin flange 31 fitting a out the adjacent end vof t e cylinder, and having perforate lugs 32 which are employed for connecting the casing with a support. The endportions of the clamp-rods 22 are extended through the casing-heads 30, and nuts 33 are screwed upon the threaded terminals of said rods to hold the heads in place. Tubular bosses 34, formed integrally with the heads 30, enable. the casing to be connected with suitable pipes or conduits for supplying air to the compartment 28, and for drawing air from the compartment 29. .j It will be clearly apparent from Fig. 2 that air from the vcompartment '28 may pass through the slots 19 of those filter-units in which said slots are at the lower side, thus entering the spaces or intake chambers between alternate pairs of the fabric tympani, and by passing through the lilter-fabric enter the -other spaces or outlet-chambers from which the slots 19 at the upper sides provide 'egress to the casing outlet-chamber 29.

At' thelower side of the casing-cylinder 27 are a plurality of openings 35, and beneath said openings isdisposed the pan 36. At the lon ltudinal edges of the pan are out-turned anges 37 which` fit upon and are held against the cylinder 27 by means of nuts 38 engaging the outer portions of screws` 39 attached to and extending outwardly from the casing. Dust received in the intake-chambers` 'of the filter-units, and falling therefrom through the slots 19 to the lower side of the casin passes through the openin pan, w ich may be taken off and the accumulated material shaken out of the an.

35 and is received in the removable with the air-inta e pipe 41 of theengine carbureter, and to the opposite end-of the filter-casing is connected the fiexlble tube 42 which extends to the air-heater 43. Unbeated air may be supplied to the filter lntake if desired, and when connection is made with "the air-heater as shown, itiis notessential that. the connections be tight,'as any leakage between the heater and casing will result merely in a slight .lowering of the air temperature. Leakage of the connectlons between the filter-casing and the carbureter should-be carefully prevented, however, as

the same would permit unfiltered or dustladen air to be mixed with the charge and drawn into the engine cylinders.

, It will be seen that my invention provides an efiicient and inexpensively constructed means for filtering or removing dust from air, in any 'situation where it is desirable that a considerable volume of air be supn plied, substantially free from suspended articles of solid matter. By the described structure, a large filter-area may be provided in a relatively small space, and the greater ortion of the solid material which accumuates in the filter may be readily removed by slightly jarring the device to cause the material to be shaken down into the removable an. The structural alterations requiredpto vary the filter-area, in adapting the device to particular requirements, involve merely the increasing or decreasing of the number of the filter-units assembled, and the provision of longer or shorter clamp-rods and a longer or shorter cylinder for the b casing. Now, having described my invention, what l claim and desire to secure by Letters Patent is:

1. In a structure of the class described,

an annular frame comprising a pair of rings having interengaged flanges, a fabric covering extending across the face and about the edges 0f one of said frame-rings and having its edges clamped between the inter-engaged fianges of the rings, the other rin having a laterally perforate portion, an

an inturned flange on the latter ring at the end opposite the fabric-covered face of the first ring. c

42. In a structure of the class'desciubed, a series of filter-units each comprising an annular frame and a fabric covering extending across one face of the frame, each frame having a laterally perforate portion, said perforate frame-portions of successive units belng at opposite sides of the series, means for 'clamping the Series of units together longitudinally, a casing inclosing the units and clamping means, and packing means extending continuously between the casing and the series of units along longitudinal lines intermediate the perforate frame-portions and about opposite sides of the series at the ends thereo I 3. In a device of the class described, a series of filter-units each comprising a cylindrical frame having radial openings in one side and a fabric covering stretched across one end thereof, said series of units arranged lcoaxially and with the open end ofeach engaging the fabric-covered end of the next, the radial openings of the frames being at alternate sides of the successive units, clamprings disposed at thel ends of the series of units, clamp-rods extending between said rings and laterally spaced from the filterunits, longitudinal packing means disposed about said clamp-rods and engaging the adjacent sides -of the filter-units, a cylindrical casing disposed about the clamping means and engaging said .longitudinal packing means, and circumferential packing means extending about laterally opposite sides of the clamp-rings intermediate the ends of the longitudinal packing means.

. 4. In a structure of the filter-unit comprising a metal ring having a fiat body-portionand an inturned marginal flange, a sheet of fabric extending across the central opening of saidv ring and about said flange, and a second ring having a cylindrical body-portion and an out-turned flange at one end of said body-portion, said fiange coacting with thel inturned flange of the first ring to clamp the edge portions of the fabric between them, said flanges being indented at diametrically opposite sides into substantial alinement with the cylindrical ody-portion of the second ring, and sait body-portion being perforate at one side circumferentially intermediate the flange indentations. y

5. In a device of the class described, a tubular frame structure, a series of fabric tympani extending transversely of said tubular frame and dividing the same longitudinally into a plurality of chambers, and

inclosing means forming intake and outlet compartments at opposite sides of the tubular frame, there being openings through the sides of the tubular frame connecting the l class described, a Y

llO

spaced relation, a tubular frame structureframe and connecting therewith to form intake and outlet compartments at ,opposite sides thereof, the tubularframe having lateral openings. connecting the successive chambers between the tympani alternatelyl wlth said intake and outlet compartments,

and means for connecting.supp1y and discharge conduits with said intake and outlet compartments.

JEROME F. HEYN. 

